Important public health questions have arisen as huge numbers of sedentary persons take up exercise in their leisure time, as if for a great natural experiment. This demands comprehensive study, especially as it may affect, favorably or adversely, the incidence of coronary heart disease (CHD); other cardiovascular disease, and total mortality. The need for answers on these issues is far too important to be ignored. The proposed work would extend observations on characteristics in youth among 50,000 male former students from Harvard and the University of Pennsylvania and 3,500 female of the latter, through observations on contemporary characteristics among surviving alumni, so as to identify changing patterns of physical activity and other habits in life-style (e.g., body weight-for-height, cigarette smoking, alcohol consumption) for any relationships to hypertensive-atherosclerotic diseases that develop later in life, and to lifespan per se. Decedents now number 12,000, leaving 41,500 survivors aged 48-88. Resources include: 1) college data from physical examination, social and athletic records; 2) self-assessed mail questionnaire responses from alumni on exercise, other life-style elements, health, familial disease pattern; 3) official death certificates. The college data span 35 years, 1916-1950, the questionnaires 19 years, 1962 to 1980. A projected mailing would update this information by case-finding and followup on trends. Analyses will examine changing patterns of physical activity and life-style characteristics for relationships to hypertensive-atherosclerotic disease incidence and total mortality. Attention will be directed to type, timing, frequency, duration, intensity, intermittency, and trends of exercise that might alter risk of cardiovascular disease (nonfatal and fatal) and total mortality. Studied likewise will be absolute measurements and changes in other life-style elements as related to these outcome variables. Multiple predictors will be examined for confounding and interactions in relation to life-style changes and disease risk. So far, life-style assessments to identify changing patterns have covered two intervals from college days to the early or mid 1960's and to the late 1970's on each of 25,000 men and 2,000 women, and extensive background of quantified information bearing on the problem at hand. The further observations and analyses proposed will help show whether and how a shift to active life-style alters CHD risk and longevity.